"Adding a third sailing along with an overall increase in customers that are considering the barge as a means of transporting their cargo sets it up for success going forward," said Rodney Oliver, VPA's interim executive director in the release.

"The next step," he added, "is to get it to five days a week."

The announcement of thrice-weekly barge service was made Monday in Richmond, and first reported by the Richmond Times Dispatch.

Barge traffic is way up in 2012 over last year. Through July the number of containers barged up the James River to the Port of Richmond on the service was 5,198, a 96 percent increase from 2,655 during the same period in 2011.

The Times-Dispatch reported that 2011 was a down year for the port because Richmond packaging company MeadWestvaco temporarily reduced operations at one of its plants.

The barge services was the result of a larger effort to reduce truck traffic on Interstate 64, to thus reduce carbon emissions and bring customers back to the Port of Richmond, after the terminal lost its two last ocean carriers during the recession.

VPA receives $4.3 million a year in state and federal congestion mitigation and air quality grants for the barge, which according to agency spokesman Joe Harris covers 85 percent of the barge service's costs.

"If you look at it in terms of roundtrip truck trips, thus far in 2012 we've taken nearly 12,500 trucks off the road and the emissions that go with that figure as well asa reduction in the wear and tear on the roads," said Heather W. Woods, VPA's director of environmental affairs in the VPA news release.

Besides MeadWestvaco, large Port of Richmond customers include Altria, Equistock and TFC Recycling.

Harris said shippers pay an average of $300 per container on the barge service.